The official who disclosed LaHood's selection as transportation secretary did so on condition of anonymity because the Obama team did not authorize the disclosure.
Obama also intends to name former Securities and Exchange Commissioner Mary Schapiro to head the much-criticized agency.
Schapiro, who currently heads a nongovernment regulatory group for securities firms, is also a former head of the Commodities Futures Trading Commission and former member of the SEC.
She has been appointed to government posts by two Republican presidents and one Democratic chief executive.
The selections came as Obama worked on completing his Cabinet, possibly in advance of a year-end holiday vacation in Hawaii with his family.
He has yet to announce choices for the Labor Department, senior intelligence positions, or the Office of US Trade Representative. Representative Xavier Becerra, Democrat of California, had been penciled in as trade representative, but he announced on Tuesday he intends to remain in the House.
In addition, numerous sub-Cabinet posts remain unfilled.
Knowledgeable officials said Dr. Gail Rosseau, a Chicago neurosurgeon, is among the final contenders to become surgeon general. These officials spoke on condition of anonymity, saying they were not authorized to discuss the appointment.
Obama introduced Vilsack and Salazar at a now-familiar ritual, a news conference where the president-elect makes his announcement, then takes a few questions from reporters.
Asked for the second day about a political scandal roiling his home state of Illinois, he said "it's a little bit frustrating" to not talk in detail about the investigation into charges that Illinois Governor Rod Blagojevich schemed to name Obama's replacement in the US Senate based on who offered the best political or financial deal.
Neither Obama nor anyone on his team has been accused of any wrongdoing. But Obama has directed transition aides to detail who on his side had contact, and what kind of contact, with Blagojevich or his staff. "There's been a lot of speculation in the press that I would love to correct," Obama said in response to a question. He said his team is "abiding by the request of the US attorney" to not release the results of the internal investigation, already compiled, until next week.
